Generally, a refrigerator is a device that keeps food fresh by having a storage compartment and a cooling air supply device that supplies cool air to the storage compartment. The refrigerator may also have an ice making chamber and an ice maker to generate ice.
An automatic ice maker generally includes an ice-making tray for storing ice-making water, an ejector for separating the ice from the ice-making tray, and an ice bucket for storing the ice separated from the ice-making tray.
Among ice-making systems for cooling ice making water, a direct cooling system is configured to have a refrigerant tube that extends into the ice making chamber to cool the ice-making water and contacts the ice making tray. In the direct cooling system, the ice-making tray receives cooling energy from the refrigerant tube in a thermally conductive manner. Therefore, the direct cooling system has an advantage in that the cooling rate of the ice-making water is relatively fast, but also has a drawback in that it produces non-transparent and misty ice.
In order to solve this problem, recently, a method has been proposed, in which a heater is applied on the bottom of the ice-making tray to grow ice in one direction to facilitate the air inside the ice-making water to dissipate to produce transparent ice, or another method has been proposed, in which crystals are grown to have a layer by layer form by setting the temperature of the ice making chamber to 0° C. or higher to remove the air inside the ice making water to produce transparent ice.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.